Recently, there has been significant growth in the use and advancement of virtual reality, augmented reality, and similar near-eye products. Common virtual reality uses include video gaming, movies, amusement ride simulators, and the like. While the popularity is driven by entertainment, the products also serve functions in training and education. For example, virtual reality headsets may be used for flight simulation training, surgery simulation for physicians, technology in the traditional classroom to spark student interest in a subject, and the like.
One method of producing a virtual reality simulation is the use of a headset. The headset contains a display with lenses placed between the eyes and display. The lenses serve to focus and reshape the image perceived by the eyes. In this manner, a 3-dimensional image is formed from 2-dimensional images from the display screen.
However, these virtual reality headsets are large in size and heavy in weight. The requirement of having a display screen a fixed distance from a user's eyes with a lens between the display and eyes requires a certain distance. Additionally, the optical components, as well as computational machinery and electronics, are bulky and heavy. Also, many conventional virtual reality headsets require another device, such as the user's smartphone, to be placed in the apparatus. Many headsets do not include a display device dedicated to the apparatus.
Even more limiting, conventional near-eye displays involve a three-way tradeoff between field of view, image resolution, and frame rate; as each of these three beneficial features may be expanded, it comes at the expense of the others in terms of optical design and computational power. Therefore, systems typically compromise all three and end up with frame rate that is so slow that images lag, resolution so slow that the display has a “screen door effect” (i.e. individual pixels can be seen rather than a smooth “retinal display”), and field of view is very limited.
What is needed is a way for high resolution displays with a wide field of view and fast frame rate to be integrated into near-eye viewing systems, such as a virtual reality headset, to improve the viewing experience. Such a device is referred to herein as a foveal display because it achieves its effects by focusing light directly into the fovea of the viewer's eyes.